What is meant by density? what are its SI unite?
please answer me..
Answer:
Density, mass of a unit volume of a material substance. ... Density offers a convenient means of obtaining the mass of a body from its volume or vice versa; the mass is equal to the volume multiplied by the density (M = Vd), while the volume is equal to the mass divided by the density (V = M/d).
Explanation:
The International System of Units is the modern form of the metric system. It is the only system of measurement with an official status in nearly every country in the world
Answer:
Density is mass per unit volume
Explanation:
SI unit is kgm3
A uniform solid ball has a mass of 20 g and a radius of 5 cm. It rests on a horizontal surface. A sharp force is applied to the ball in the horizontal direction 9 cm above the surface. The force rises linearly from 0 to a peak value of 40,000 N in 10^(-4) s then decreases linearly to 0 in another 10^(-4) s. (The moment of inertia for a solid ball is 2/5 mR^2 ) What is the velocity of the ball after the impact
Answer:
i think the answer is 32 something
Explanation:
why do trucks need a runaway ramp
Answer:
in case they lose control going downhill.
Explanation:
which is why they usually have a steep incline and are quite long. You see them used typically when the trucks brakes fail.
What are the functionsssss of geostationary satellite and non-geostationary satellite?
Answer:
What is the difference between a geostationary satellite and a non-geostationary satellite? Geostationary (GSO) satellites occupy an orbital position 36,000 km above the earth, and remain in a stationary position relative to the Earth itself.
A properly exposed photograph is taken at f/16 and 1/120s. What lens opening is required if the shutter speed is 1/60s
Answer:
f / 8
Explanation:
The f-number is the ratio of the lens's focal length to its diameter and is a measure of the intensity of the light reaching the CCD. The smaller the greater the intensity of the light
I = D / f
f-number = f / D
I = 1 / f-number
the energy deposited in the CCD is proportional to the intensity of the light and the exposure time (Δt)
E = I Δt
E = 1 /f-number Δt
in the exercise they indicate that the system is well exposed (the image is sharp and clear) for fo-number = f / 16
Δt = exposure time = 1/120 s
E = [tex]\frac{1}{120} \ \ \frac{1}{fo-number}[/tex]
indicate that the exposure time has been changed to Δt = 1/60 s, which should be the f₁-number
E = [tex]\frac{1}{60} \ \ \frac{1}{f_1-number}[/tex]
the energy deposited must be the same per location we can equal the expressions
[tex]\frac{1}{120} \ \frac{1}{f_o-number} = \frac{1}{60} \ \frac{1}{f_1-number}[/tex]
f₁-number = [tex]\frac{60}{120} \ \ \frac{1}{fo-number}[/tex]
f₁-number = ½ 16
f₁-number = 8
so the system should be set to f / 8
a man counts 6 waves on a pond in 10 seconds. the distance between them is 40 cm. what is their speed?
Answer:
so a man counts 6 waves on a pound in 10 second
Explanation:
6×10 = 60
60/40
so the answer is3
The Moon is attracted to the Earth. The mass of the Earth is 6.0x1024 kg and the mass of the Moon is 7.4x1022 kg. If the Earth and Moon are 345,000 km apart, what is the gravitational force between them?
Sorry I don't know the answer
HELP PLZ
A baseball player hits a pop-up. The ball was hit when it was 3 feet off the ground with an initial
upward velocity of 80 ft/s. How long will it take for the ball to reach a height of 10 feet off the
ground, on the way down?
Answer:
Explanation:
Use the equation
[tex]h(t)=-16t^2+v_0t+h_0[/tex]
where h(t) is the height after a certain amount of time goes by, v0t is the initial upwards velocity, and h0 is the initial height of the projectile. For us:
h(t) = 10
v0t = 80
h0 = 3 and filling in:
[tex]10=-16t^2+80t+3[/tex] and get everything on one side to factor:
[tex]0=-16t^2+80t-7[/tex]
This factors to
t = .09 sec and 4.9 sec. Let's interpret this.
The time of .09 is when the ball reached 10 feet on the way up, and
the time of 4.9 is when the ball reached 10 feet on the way back down. That's the height we need, 4.9 seconds.
Which of the following creates the night-and-day cycle experienced on Earth?
A) Orbit of Earth around the Sun
B) Rotation of the Sun
C) Rotation of the Earth
D) Tilt of the axis of Earth
Help pls... 100points
1 Answer:
The pitch of a sound depends on
a. frequency
b. intensity
c. amplitude
d. quality
2 Answer:
The loudness of a sound depends on
a. frequency
b. intensity
c. overtones
d. timbre
3 Answer:
The number of sound waves per unit time is called
a. amplitude
b. wavelength
c. speed
d. frequency
4 Answer:
The blending of fundamental tone and overtones produces a sound's
a. intensity
b. pitch
c. timbre
d. loudness
5 Answer:
Sonar is used
a. to locate objects in water
b. to determine underwater distances
c. for both a and b
d. for neither a nor b
6 Answer:
Sounds of frequencies below 20 Hz are called
a. fundamentals
b. overtones
c. ultrasonic sounds
d. infrasonic sounds
7 Answer:
A sound is music if it has
a. a definite pitch
b. a pleasing quality
c. rhythm
d. all of these characteristics
8 Answer:
The stirrup is a part of the
a. outer ear
b. middle ear
c. inner ear
d. cochlea
9 Answer:
An example of a percussion instrument is a (an)
a. trumpet
b. harp
c. drum
d. flute
10 Answer:
The speed of sound depends on
a. temperature
b. density
c. elasticity
d. all of these factors
11 Answer:
Sounds with frequencies above 20,000 Hz are called _____.
12 Answer:
The science of sound is called _____.
13 Answer:
High-frequency waves are used in a sound navigation and ranging
system called _____.
14 Answer:
Sounds produced when sections of a string vibrate separately are
called _____.
15 Answer:
Sound without pleasing quality, identifiable pitch, and repeating
patterns is called _____.
16 Answer:
The speed of sound decreases with increasing temperature.
a. true
b. false
17 Answer:
Sound waves are transverse.
a. true
b. false
18 Answer:
The decibel is a unit of pitch.
a. true
b. false
19 Answer:
A change in the pitch of a sound due to motion of source or
receiver (observer) is called the Doppler effect.
a. true
b. false
20 Answer:
Guitars and cellos are examples of percussion instruments.
a. true
b. false
Answer:
Explanation:
1. a as pitch depends on frequency
2. b as loudness depends on intensity
3. d as that is definition of frequency
4. c as that is definition of timbre
5. c as sonar can do both
6. d as that is definition of infrasound
7. d
8. b as that is one of three bones in the middle ear
9. c as you hit the drum to make sound
10. d
11. ultrasound
12. acoustics
13. ultrasound
14. harmonics? or resonance?
15. noise
16. b
17. b
18. b
19. a
20. b
A , D
B , C
C , B
B , D
Answer:
c and b
Explanation:
hope this helped!
Your _________ is simply your weight-to-height ratio which can be calculated using certain body measurements.
O health
O size
O weight loss
O BMI
Answer:
SiZe
Explanation:
bad bunny is the best!!!
A ray of light traveling in water hits a glass surface. The index of refraction of the water is 1.33, and that of the glass is 1.50. At what angle with the plane of the surface must the incident ray strike the glass in order that the polarization of the reflected ray is the greatest
Answer:
[tex]\mu=41.5\textdegree[/tex]
Explanation:
From the question we are told that:
Water index of refraction [tex]i_w=1.33[/tex]
Glass index of refraction [tex]i_g=1.50[/tex]
Generally the equation for Brewster's law is mathematically given by
[tex]\theta=tan^{-1}(\frac{i_g}{i_w})[/tex]
[tex]\theta=tan^{-1}(\frac{1.50}{1.33})[/tex]
[tex]\theta=48.44 \textdegree[/tex]
Therefore Angle of incident to plane \mu (normal at 90 degree to the surface)
[tex]\mu=90\textdegree-\theta[/tex]
[tex]\mu=90\textdegree-48.44\textdegree[/tex]
[tex]\mu=41.5\textdegree[/tex]
sino ang legendary hacker ng pilipinas?
Answer:
Onel de guzman now he's 44,the first world's computer virus has admitted to his guilt.
(●’◡’●)ﾉ (ᗒᗣᗕ)՞ ༼ つ ◕◡◕ ༽つ
Conditional waves contain a crest, trough, wavelength, and amplitude
True or False?
Answer:
True
Explanation:
Students have 4 different pairs of sunglasses, each with lenses where the polarization filter is oriented in different directions (indicated by the direction of lines drawn on the lenses below). They are planning to ride rafts down a river on a sunny day where there is lots of glare on the water. Which pair would they want to wear to eliminate the glare from the sun
Answer:
the lens you must select has an angle of 143º measured with respect to the horizontal, this angle is 53º with respect to the vertical.
Explanation:
The glare is caused by the reflection of light in the water, the polarization of the reflected light is polarized in a direction parallel to the surface of the water, the polarization is total for the angles
n = tan [tex]\theta_{p}[/tex]
\theta_{p} = tan⁻¹ n
the refractive index for seawater is 1.33
\theta_{p}= tan⁻¹ 1.33
\theta_{p} = 53º
for this angle the light is totally polarized, for the other angles the polarization is partial.
Based on this, the lenses must eliminate this polarization, so its polarization direction must have 90º with respect to this polarization,
\theta_{lens} = 53 +90
\theta_{lens}= 143º
Therefore, the lens you must select has an angle of 143º measured with respect to the horizontal, this angle is 53º with respect to the vertical.
A lens that could work is one that is polarized 45º with respect to the vertical.
The glass that is worn to eliminate glare must be able to remove glare away from the user.
What are sunglasses?The term sunglasses refers to the kind of glasses that are worn to prevent glare from the sun. This is because the glasses are made of polaroid materials that eliminate glare.
The question is incomplete as the sunglasses are not shown. However, the glass that is worn to eliminate glare must be able to remove glare away from the user.
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A nylon rope that has a 0.73 cm radius and is 12 meters long is used to lift a 24 kg object straight up. If the object is lifted at constant velocity, how much is the rope stretched by? The Young's modulus of the nylon is 5.0 × 109 N/m2 and use 9.81 m/s2 for the acceleration of free fall. Express your answer in centimeters and round to the nearest hundredth.
Answer:
The rope is stretched by 0.3373 cm
Explanation:
As we know
Youngs Modulus ([tex]5.0 * 10^9[/tex] N/m2) is Stress divided by strain
Stress = force/Area = (65*9.8)/(pi * (7.3*10^-3)^2)
Starin = change in length/original length of the rope = l/12 meters
Substituting the given values we get
[tex]5.0 * 10^9[/tex] N/m2 = {([tex]\frac{\frac{24*9.8}{\pi *(7.3*10^{-3})^2} }{\frac{\delta L}{L} }[/tex])
[tex]5.0 * 10^9[/tex] N/m2 = {([tex]\frac{\frac{24*9.8}{\pi *(7.3*10^{-3})^2} }{\frac{\delta L}{12} }[/tex])
[tex]\frac{\delta L}{12} = \frac{\frac{65*9.8}{pi * (7.3*10^-3)^2} }{5.0 * 10^9}[/tex]
The rope is stretched by 0.3373 cm
URGENT: Testing shows that a sample of wood from an artifact contains 50% of the
original amount of carbon-14. Given that the half-life of carbon-14 is 5730
years, how old is the artifact?
O A. 22,920 years
B. 11,460 years
C. 5730 years
O D. 2865 years
Answer:
Im so so sorry but I do now know how to do this
Explanation:
7
The periodic table displays
A.
only the important compounds that exist in the world.
OB.
all of the known compounds that exist in the world today.
C.
only the important elements that exist in the world.
D.
all of the known tements that exist in the world today.
What’s the answer to 19 please please help me
Answer:
A.
Explanation:
A po sa tingin ko
sana po makatulong
a test tube has a diameter of 3cm . how many turns would a piece of thread of length 90.42 make round test tube
Answer:
4.8 turns would be made around the tube
Explanation:
You need the circumference of the tube since it's just a lifted circle
2×pi×3=18.85
90.42/18.85=4.79
And round that to 4.8
To understand the first law of thermodynamics and its origin. By relating heat, thermal energy, and work, the first law lays the groundwork for thermodynamics. The first law of thermodynamics generalizes the concept of energy conservation to include heat energy. You are probably already aware that loss of total mechanical energy (e.g., from nonconservative forces such as friction) does not destroy energy, but rather converts mechanical energy into thermal energy. This process, as well as the reverse process (conversion of thermal energy into mechanical energy), can be described quantitatively by the first law. Like the law of mechanical energy conservation that it generalizes, the first law relates the changes in energy that occur from the beginning to the end of some process. The first law involves the following physical quantities Using your knowledge of energy conservation, express AEth in terms of Q and W. • W: work done on the system by the outside world, Q: heat added to the system by the outside world, and AEth: thermal energy change of the system.
Answer:
okay
Explanation:
Which best describes a tsunami?
Answer:
A tsunami is a series of waves in a water body caused by the displacement of a large volume of water, generally in an ocean or a large lake. Earthquakes, volcanic eruptions and other underwater explosions above or below water all have the potential to generate a tsunami. Unlike normal ocean waves, which are generated by wind, or tides, which are generated by the gravitational pull of the Moon and the Sun, a tsunami is generated by the displacement of water.
Answer:
A tsunami is series of waves caused by heavy winds. Hurricanes can cause tsunami
Explanation:
How were the barriers to critical thinking presented?
Answer:
At a personal level, barriers to critical thinking can arise through: ... self-centred or societal/cultural-centred thinking (conformism, dogma and peer-pressure) unconscious bias, or selective perception. an inability to be receptive to an idea or point of view that differs from your own (close-mindedness)
Explanation:
Sources A and B emit long-range radio waves of wavelength 360 m, with the phase of the emission from A ahead of that from source B by 90°. The distance rA from A to a detector is greater than the corresponding distance rB from B by 130 m. What is the magnitude of the phase difference at the detector?
Answer:
[tex]X=165 \textdegree[/tex]
Explanation:
From the question we are told that:
Wavelength [tex]\lambda =360m[/tex]
Angle [tex]\theta=90 \textdegree[/tex]
Distance variation [tex]d=130m[/tex]
Generally the equation for phase difference X is mathematically given by
[tex]X=\theta+\frac{d}{\lambda}*100[/tex]
[tex]X=90+\frac{150}{360}*100[/tex]
[tex]X=165 \textdegree[/tex]
Therefore Phase difference X is given as
[tex]X=165 \textdegree[/tex]
2. A company hires a security firm to patrol their stores and watch out for thieves. What is this an example of?
In a case whereby the company hires a security firm to patrol their stores and watch for thieves, this is an example of Inventory control.
Inventory Control: What Is It?Inventory control, also known as stock control, is the procedure used to guarantee that a business has the appropriate amount of supplies on hand. As long as internal and production controls are in place, the business can meet client demand and maintain financial flexibility.
The general definition of inventory control or stock control is "the action of verifying a shop's stock." It is the process of making sure that a business has the appropriate amount of supply on hand.
Learn more about Inventory at:
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A satellite of mass m is in a circular orbit of radius R2 around a spherical planet of radius R1 made of a material with density ρ. ( R2 is measured from the center of the planet, not its surface.) Use G for the universal gravitational constant.
A) Find the kinetic energy of this satellite, K
Express the satellite's kinetic energy in terms of G, m, π, R1, R2, and ρ.
B) Find U, the gravitational potential energy of the satellite. Take the gravitational potential energy to be zero for an object infinitely far away from the planet.
Express the satellite's gravitational potential energy in terms of G, m, π, R1, R2, and ρ.
C) What is the ratio of the kinetic energy of this satellite to its potential energy?
Express K/U in terms of parameters given in the introduction.
Answer:
a)
get mass of planet:
ρ = M / V
V = 4/3 * R_1^3
M = ρ * V
M = ρ * 4/3 * R_1^3
equate force equations:
F = (GMm) / r^2 // r = R_2
F = ma
a = v^2/R_2
F = m * (v^2/R_2)
m * (v^2/R_2) = (GMm) / R_2^2
plug in and solve v^2:
m * (v^2/R_2) = (G * (ρ * 4/3 * R_1^3) *m) / R_2^2
v^2 = (G * ρ * (4/3) * π * R_1^3) / R_2
put into kinetic energy equation:
K = 1/2 * m * v^2
K = 1/2 * m * (G * ρ * (4/3) * π * R_1^3) / R_2
B)
givens:
U = -(GmM) / R_2
plug in mass of planet:
U = -(G * m * ρ * 4/3 * R_1^3) / R_2
C)
use previous equations and do some algebra:
K/U = (1/2 * m * (G * ρ * (4/3) * π * R_1^3) / R_2) * -(R_2 / (G * m * ρ * 4/3 * R_1^3))
K/U = -1/2
Ice is placed in cool water. What happens to the temperature of the ice and the water?
Answer:
Explanation:
ice absorbs heat from the water. As the water molecules lose energy, they begin to slow down, and consequently to cool. So, it's kind of the opposite of what we might think: when we put ice in water, the ice doesn't give its cold to the water, it takes heat from the water.
A plane is heading south with a velocity of 150 kilometers/hour. It experiences a tallwind with a velocity of 20 kilometers/hour. Find the resultant
velocity of the plane.
A.120 kilometers/hour to the south
B.148 kilometers/hour to the north
C.170 kilometers/hour to the south
D.130 kilometers/hour to the north
E.150 kilometers/hour to the south
Answer: 170km/hr to the South
Explanation:
The resultant velocity of the plane ilwill be gotten by adding the value of the velocities of the plane with the tallwind. It should be noted that the direction of the wind is.takwn into consideration.
Therefore, the resultant velocity of the plane will be:
= 20km/hr + 150km/hr
= 170km/hr to the South
Answer:
Resultant Velocity = 20 km/h + 150 km/h = 170 km/h
Explanation:
map.
Which best describes the motion of the object
between 1 and 4 seconds?
کے م
The object has decreasing acceleration and
increasing velocity.
The object has positive acceleration and eventually
stops.
The object has decreasing acceleration and
decreasing velocity.
The object has negative acceleration and eventually
stops.
Answer:
The object has decreasing acceleration and decreasing velocity.